1. Field of the Invention
The present invention generally relates to a channel estimator for a wireless local area network (WLAN) and, more particularly to a channel estimator characterized in that adjustment in channel estimation is adaptively performed at anytime during the delivery of a signal packet so as to achieve fast convergence as well as accurate channel estimation.
2. Description of the Prior Art
Recently, wireless local area networks (WLAN's) have been widely studied, discussed and developed. In OFDM (Orthogonal Frequency Division Multiplexing)-based WLAN technology, channel estimation has become one of the most important issues. To date, short and long preambles are used in most channel estimation applications. The short and long preambles are usually disposed at the front end of a transmitted packet. However, after the packet is transmitted in the WLAN for a period of time, the channel for signal transmission varies with time and/or space. Therefore, channel estimation by using the preambles is not sufficient for the rest of the data in the transmitted packet after the channel has varied.
Meanwhile, channel estimation results in error signals that adversely affect the accuracy in data demodulation without adjustment in channel estimation, thereby causing serious demodulation errors.